1. Field of the Invention
This invention relates to a hard surface cleaning composition, and in particular to an aqueous floor cleaning composition.
While the composition of the present invention is primarily intended for cleaning restaurant kitchen floors, the composition can be used to clean other solid surfaces such as the floors of food processing plants which are subject to food and/or grease soiling.
2. Discussion of the Prior Art
Slipping and falling by persons working in restaurant kitchens is not uncommon. In fact, most restaurant kitchen injuries are the result of falling. Slipping occurs on wet floors, on food on the floors and especially on fat near frying equipment. Commercially available chemical degreasers remove some fat from floor surfaces, but are not particularly effective at removing fat from grout or other porous surfaces. The result is speeding re-soiling of floors immediately following cleaning.
An object of the present invention is to provide a hard surface cleaning composition for such floors which effectively degreases an entire floor area including tile grout and porous surfaces.
Another object of the invention is to provide a hard surface cleaning composition which is progressively active, i.e. continues to be active over a relatively long period of time after being applied to a surface.
In general terms, the composition of the present invention includes at least one surfactant; an enzyme mixture for breaking down organic compounds such as fats, oils, grease and starch; nonpathogenic bacteria for degrading and assimilating organic compounds such as fats, oils and greases, starch and proteins; and water.
More specifically, the invention provides an aqueous hard surface, liquid cleaning composition containing an anionic and a nonionic surfactant; an enzyme mixture such as lipase (triacylglycerol acylhydrolase, E.C.3.1.1.3)/alpha-amylase (E.C.3.2.1.1); an enzyme activator such as calcium chloride dihydrate for rendering the enzymes more active; nonpathogenic Bacillus bacteria; a stabilizer such as anhydrous sodium acetate; a buffer such as tris (hydroxymethyl) aminomethane and water.
The surfactants ensure good bioavailability of the dirt, working instantly when the composition is applied to a surface. The calcium chloride dihydrate stabilizes the lipase and removes free fatty acids from the reaction system by the formation of Ca2+ salt, thereby preventing inhibition of the enzyme and reassociation of the free fatty acids with hydrolyzed fat molecules (diglycerides, monoglycerides and glycerol).
In addition to lipase, the composition can also contain an alpha-amylase, which broadens the cleaning activity of the formulation. The enzymes break down the organic compounds on the hard surface. The enzyme lipase catalyzes the hydrolysis of triacylglycerides (fats) into diglycerides, monoglycerides, free fatty acids and glycerol. The enzyme alpha-amylase catalyzes the hydrolysis of polysaccharides such as starch into smaller sugars such as maltose. The activity of the enzymes are immediate and long lasting, starting as soon as the composition is applied to the surface being treated and lasting as long as the enzymes are in good condition and not retroinhibited by accumulation of metabolites. Amylase enzyme will also keep active as long as a minimum of dampness is maintained on the surface and in the tile grout or other cracks. The lipase activity is independent of dampness and can be active even in low water activity conditions. In tile grout, the activity can last for hours. The enzyme mixture is lipolytic and amylolytic, but not proteolytic, since the latter activity would work against enzyme protein.
The bacteria used in the composition (Bacillus subtilis and Bacillus amyloliquefaciens) play a major role in the composition described herein. The activity of the bacteria is progressive, i.e. the bacteria can take up to three hours to become fully active, and the bacterial activity can last up to twenty-four hours in normal humidity. The smaller molecules produced by the hydrolysis of the complex organic compounds by the enzyme mixture become available for the bacteria. Then the bacteria will start growing and producing their own lipase and amylase enzymes, becoming very effective at degrading various organic compounds including fats and starch.